[llvm] [AArch64][SVE] Fold ADD+CNTB to INCB and DECB (PR #118280)

[Ricardo Jesus via llvm-commits]

rj-jesus wrote:

For the cases that benefit from the fast INCB I agree, it might not be the tightest code but it shouldn't lose in performance to the ADDVL alternative.

https://github.com/llvm/llvm-project/pull/118280